Oak Ridge-based US start-up Standard Nuclear has begun producing high-assay low-enriched uranium (HALEU) tri-structural isotropic (TRISO) fuel at its primary manufacturing facility located on a 36.8-acre campus at the historic Heritage Center (former K-25 nuclear site) in Oak Ridge, Tennessee.
Although the facility began operation in 2024, Standard Nuclear only emerged from stealth in June 2025. The current facility spans 19,000 square feet and is capable of producing approximately 500 kg of TRISO fuel annually. However, with the recently announced $140m million Series A funding, the company plans to expand the site to reach a production capacity of more than 2 tonnes by mid-2026.
Under a first-of-its-kind agreement signed in December 2025, the facility operates under the US Department of Energy’s (DOE) safety authority rather than the Nuclear Regulatory Commission (NRC). This regulatory pathway was designed to bypass the multi-year NRC licensing process, allowing the facility to immediately begin fabricating fuel for pilot reactors scheduled for 2026.
Earlier in January, the facility received its first physical shipment of HALEU feedstock from the DOE’s Savannah River Site. The material is intended for processing into TRISO fuel for Radiant Industries’ Kaleidos reactor, one of the 11 projects aiming to achieve criticality by 4 July under DOE’s Reactor Pilot Program.
For the past year, Standard Nuclear has been operating its manufacturing line in Oak Ridge using surrogate materials (such as natural or depleted uranium) to calibrate the machinery. This demonstrated the ability to make the physical TRISO particles, but not nuclear fuel. The facility has now officially transitioned to using the HALEU feedstock provided by DOE to produce fuel that can sustain a nuclear reaction. Specifically, this production run will be for Radiant’s “Kaleidos” reactor. This marks the first time a US private, commercial facility has begun manufacturing HALEU TRISO fuel under DOE safety oversight.
“Standard Nuclear has successfully achieved numerous pivotal strategic and commercial objectives since our founding one year ago, leading to the remarkable occasion today as we begin producing HALEU TRISO,” said Standard Nuclear CEO Kurt Terrani. “This successful Series A raise ensures we have the capital required to fully execute on our expansion and growth strategy across various products and services based on our technical manufacturing capabilities and industry-leading fuel production expertise. With this funding, we are positioned to accelerate our roadmap, scale operations, and deliver on the promise to fuel the next generation of reactors powering industry, defence, and space.”
According to Standard Nuclear, the $140M in Series A funding was from investors led by Decisive Point with participation from new investors Chevron Technology Ventures, StepStone Group, XTX Ventures, and existing investors Welara, Fundomo, Andreessen Horowitz, Washington Harbour Partners, and Crucible Capital, among many others. “This latest capital raise will support Standard Nuclear’s rapid buildout of new fuel development and fabrication infrastructure beyond the company’s existing operational and privately funded commercial-scale TRISO manufacturing line,” the company said.
Standard Nuclear said it has executed multiple strategic and commercial milestones in its first 12 months of operations. It was the first company selected in August 2025 for DOE’s Fuel Line Pilot Program, which fast-tracks the fabrication of advanced fuel for next-generation reactors. It also formed a joint venture with Framatome in September to supply commercial quantities of TRISO fuel and proprietary advanced reactor products. The company’s rapid operational start has been aided by its acquisition of Ultra Safe Nuclear Corporation’s (USNC) fuel manufacturing assets following that company’s bankruptcy in October 2024.
In addition to its Oak Ridge facility, in late 2025, the company began developing a second manufacturing site, the Standard Nuclear-West (SN-West) facility, located in Idaho Falls, Idaho. The facility is situated near the Idaho National Laboratory (INL) to provide immediate proximity to the Microreactor Applications Research and Validation (MARVEL) testbed and the National Reactor Innovation Centre (NRIC).
SN-West is specifically designed to handle final fuel assembly and “hot” integration. While the Oak Ridge site produces the TRISO particles and pellets, the Idaho site will be used to load that fuel into reactor cores and perform final safety checks before the units are moved to their test pads. The site is being built to support the DOE Reactor Pilot Program, providing a dedicated workspace for partners such as Radiant Industries and Antares to integrate their hardware with the fuel produced in Tennessee. Construction and fit-out began in October 2025, with the goal of being fully operational by the second quarter of 2026
This second facility completes Standard Nuclear’s “hub-and-spoke” model: high-volume TRISO particle production Oak Ridge and precision core loading and reactor integration in Idaho. This allows the company to maintain a continuous fuel line from raw feedstock to a ready-to-fire reactor core without long-distance transport of fully assembled fuelled cores.
However, transporting HALEU TRISO fuel between the facilities in Tennessee and Idaho will need to meet strict federal regulations, involving specialised packaging, and robust security measures coordinated by DOE and other agencies.
